In this article, we examined the relation between time pressure and organizational citizenship behavior and the moderating role of conscientiousness. Two hundred and thirty employee working in service sector of different cities located in Pakistan participated in this study. Time lag research design was adopted in this study. Data for time pressure and conscientiousness were collected at time 1 (Self-Reported) and data for organizational citizenship behavior was collected at time 2 (SupervisoryRating Method). Results of this study revealed that time pressure and conscientiousness was negatively related to organizational citizenship behavior. Furthermore, it was found that conscientiousness act as moderator in the relations between time pressure and organizational citizenship behavior. The findings make study significant for improving organizational behavior.